Su.pr was developed by the same geniuses that brought us StumbleUpon and has the added bonus of superior analytics and added traffic to the link. How it works is that users enter the desired URL and then shorten, copy and paste it directly to the site of their choice. Then, the number of clicks are tracked and it’s also simultaneously submitted to the StumbleUpon system, which reaches an entirely new audience. It also tracks the clicks that occur on StumbleUpon.
One of the coolest features is that it tracks what time people are clicking on the links, which provides you with the optimal times to post new content – and users can schedule tweets based on the optimal times as well. So, all in all, with added traffic and clarity behind click maximization, su.pr is, well, super.